1. Field of the Invention
The present invention relates to a vehicle seat having a tubular frame and elastomeric fabric seating surface.
2. Background Art
Vehicle seats have long been formed of interconnected spring support elements covered by padding material and upholstery. Vehicle seat construction has been simplified in recent years by utilizing structural foam supported by frames or rigid panels that are covered by fabric, vinyl or leather upholstery.
Office chairs are known that are formed by a frame having mesh webbing covering the seating surfaces thereof. These designs have not been effectively adapted for automobile seating purposes.
The above problems and disadvantages are addressed by the present invention that answers the long felt need of providing a elastomeric seating system that is adjustable and well suited to the requirements of a vehicle seat.
The invention is directed to an elastomeric fabric, self-supporting vehicle seat having a rugged tubular frame that is highly contoured to provide three dimensional occupant support. The seat frame must be securely wrapped with sufficient padding for a passenger""s body resting on elastomeric seating surfaces. Such a seat must be able to maintain its desirable characteristics through a wide range of conditions including the full range of temperatures encountered in a vehicle interior. The invention also may relate to an elastomeric seat having belts that do not have a xe2x80x9csling-shotxe2x80x9d effect and the seat must not allow an occupant""s body to xe2x80x9csubmarinexe2x80x9d in the event of an impact. The vehicle seating system may also have a lumbar support that is easily adjustable and provides a comfortable ergonomic shape.
According to one aspect of the invention, a vehicle seat for a person riding in a vehicle is provided by a contoured tubular frame, at least one belt, and an elastomeric mesh seating surface. The contoured tubular frame defines the edges of a seat base and a seat back. At least one belt is secured to the tubular frame. The elastomeric mesh seating surface is secured to the tubular frame and the belt wherein the belt draws the mesh seating surface into a concave shape within the tubular frame to provide a concave seating surface.
According to another feature of the invention, a contoured tubular frame defines the edges of a seat base and a seat back providing a supportive curvature. The frame is wrapped in foam padding to provide comfort and impact protection. The geometry of the frame is configured to provide an aesthetically pleasing seating surface contour.
According to yet another aspect of the invention, two tensioned belts may be provided in each of the seat base and seat back with the tensioned belts in the seat base extending longitudinally relative to the vehicle while the two tensioned belts in the seat back extending substantially vertically on the seat back. The tensioned belts may be provided that are secured to an upper portion of the seat back of the tubular frame and to a portion of the front seat base of the tubular frame. The belts support the elastomeric mesh seat fabric to form a comfortable three-dimensional elastomeric mesh seating surface that wraps around a seat occupant. The tensioned belts are made of a material that is not subject to changes in elasticity through a wide range of environmental conditions.
The tensioned belts are sewn, fastened, adhered or otherwise secured to the elastomeric mesh seat fabric and anchored to elastomeric foam that is wrapped around portions of the frame. The mesh seating surface is secured to the tensioned belts to minimize excursion of the mesh seating surface. The foam adds to the comfort of the seats. Deceleration loads on impact are transmitted by the belts to fully compress the foam and inhibit belt travel.
A further aspect of the invention relates to the concept of providing a cushion, or foam block, under the elastomeric seating surface near the front of the seat bottom cushion to prevent submarining. The cushion is sufficiently rigid so that it functions to block the occupant from sliding out from under a lap belt at impact. The foamblock may be wrapped around the frame with the mesh seating surface being wrapped around the foam block to provide both comfort and impact protection.
The invention also relates to providing an adjustable eccentric lumbar cushion that provides firm lower back support. The eccentric lumbar cushion may be rotated to modify the degree of back rest curvature. The eccentric lumbar cushion is mounted on a flexible shaft that allows for some movement of the cushion to aid in absorbing vibration. In an impact, the flexible shaft may absorb some of the deceleration loads applied to the occupant.
These and other aspects and advantages of the present invention will be better understood in view of the attached drawings and following detailed description of the illustrated modes of practicing the invention.